Subversion Repositories DevTools

package Archive::Zip::ZipFileMember;

use strict;

use vars qw( $VERSION @ISA );

BEGIN {

    $VERSION = '1.57';

    @ISA     = qw ( Archive::Zip::FileMember );

}

use Archive::Zip qw(

  :CONSTANTS

  :ERROR_CODES

  :PKZIP_CONSTANTS

  :UTILITY_METHODS

);

# Create a new Archive::Zip::ZipFileMember

# given a filename and optional open file handle

#

sub _newFromZipFile {

    my $class              = shift;

    my $fh                 = shift;

    my $externalFileName   = shift;

    my $possibleEocdOffset = shift;    # normally 0

    my $self = $class->new(

        'crc32'                     => 0,

        'diskNumberStart'           => 0,

        'localHeaderRelativeOffset' => 0,

        'dataOffset' => 0,    # localHeaderRelativeOffset + header length

        @_

    );

    $self->{'externalFileName'}   = $externalFileName;

    $self->{'fh'}                 = $fh;

    $self->{'possibleEocdOffset'} = $possibleEocdOffset;

    return $self;

}

sub isDirectory {

    my $self = shift;

    return (substr($self->fileName, -1, 1) eq '/'

          and $self->uncompressedSize == 0);

}

# Seek to the beginning of the local header, just past the signature.

# Verify that the local header signature is in fact correct.

# Update the localHeaderRelativeOffset if necessary by adding the possibleEocdOffset.

# Returns status.

sub _seekToLocalHeader {

    my $self          = shift;

    my $where         = shift;    # optional

    my $previousWhere = shift;    # optional

    $where = $self->localHeaderRelativeOffset() unless defined($where);

    # avoid loop on certain corrupt files (from Julian Field)

    return _formatError("corrupt zip file")

      if defined($previousWhere) && $where == $previousWhere;

    my $status;

    my $signature;

    $status = $self->fh()->seek($where, IO::Seekable::SEEK_SET);

    return _ioError("seeking to local header") unless $status;

    ($status, $signature) =

      _readSignature($self->fh(), $self->externalFileName(),

        LOCAL_FILE_HEADER_SIGNATURE);

    return $status if $status == AZ_IO_ERROR;

    # retry with EOCD offset if any was given.

    if ($status == AZ_FORMAT_ERROR && $self->{'possibleEocdOffset'}) {

        $status = $self->_seekToLocalHeader(

            $self->localHeaderRelativeOffset() + $self->{'possibleEocdOffset'},

            $where

        );

        if ($status == AZ_OK) {

            $self->{'localHeaderRelativeOffset'} +=

              $self->{'possibleEocdOffset'};

            $self->{'possibleEocdOffset'} = 0;

        }

    }

    return $status;

}

# Because I'm going to delete the file handle, read the local file

# header if the file handle is seekable. If it is not, I assume that

# I've already read the local header.

# Return ( $status, $self )

sub _become {

    my $self     = shift;

    my $newClass = shift;

    return $self if ref($self) eq $newClass;

    my $status = AZ_OK;

    if (_isSeekable($self->fh())) {

        my $here = $self->fh()->tell();

        $status = $self->_seekToLocalHeader();

        $status = $self->_readLocalFileHeader() if $status == AZ_OK;

        $self->fh()->seek($here, IO::Seekable::SEEK_SET);

        return $status unless $status == AZ_OK;

    }

    delete($self->{'eocdCrc32'});

    delete($self->{'diskNumberStart'});

    delete($self->{'localHeaderRelativeOffset'});

    delete($self->{'dataOffset'});

    return $self->SUPER::_become($newClass);

}

sub diskNumberStart {

    shift->{'diskNumberStart'};

}

sub localHeaderRelativeOffset {

    shift->{'localHeaderRelativeOffset'};

}

sub dataOffset {

    shift->{'dataOffset'};

}

# Skip local file header, updating only extra field stuff.

# Assumes that fh is positioned before signature.

sub _skipLocalFileHeader {

    my $self = shift;

    my $header;

    my $bytesRead = $self->fh()->read($header, LOCAL_FILE_HEADER_LENGTH);

    if ($bytesRead != LOCAL_FILE_HEADER_LENGTH) {

        return _ioError("reading local file header");

    }

    my $fileNameLength;

    my $extraFieldLength;

    my $bitFlag;

    (

        undef,    # $self->{'versionNeededToExtract'},

        $bitFlag,

        undef,    # $self->{'compressionMethod'},

        undef,    # $self->{'lastModFileDateTime'},

        undef,    # $crc32,

        undef,    # $compressedSize,

        undef,    # $uncompressedSize,

        $fileNameLength,

        $extraFieldLength

    ) = unpack(LOCAL_FILE_HEADER_FORMAT, $header);

    if ($fileNameLength) {

        $self->fh()->seek($fileNameLength, IO::Seekable::SEEK_CUR)

          or return _ioError("skipping local file name");

    }

    if ($extraFieldLength) {

        $bytesRead =

          $self->fh()->read($self->{'localExtraField'}, $extraFieldLength);

        if ($bytesRead != $extraFieldLength) {

            return _ioError("reading local extra field");

        }

    }

    $self->{'dataOffset'} = $self->fh()->tell();

    if ($bitFlag & GPBF_HAS_DATA_DESCRIPTOR_MASK) {

        # Read the crc32, compressedSize, and uncompressedSize from the

        # extended data descriptor, which directly follows the compressed data.

        #

        # Skip over the compressed file data (assumes that EOCD compressedSize

        # was correct)

        $self->fh()->seek($self->{'compressedSize'}, IO::Seekable::SEEK_CUR)

          or return _ioError("seeking to extended local header");

        # these values should be set correctly from before.

        my $oldCrc32            = $self->{'eocdCrc32'};

        my $oldCompressedSize   = $self->{'compressedSize'};

        my $oldUncompressedSize = $self->{'uncompressedSize'};

        my $status = $self->_readDataDescriptor();

        return $status unless $status == AZ_OK;

        # The buffer withe encrypted data is prefixed with a new

        # encrypted 12 byte header. The size only changes when

        # the buffer is also compressed

        $self->isEncrypted && $oldUncompressedSize > $self->{uncompressedSize}

          and $oldUncompressedSize -= DATA_DESCRIPTOR_LENGTH;

        return _formatError(

            "CRC or size mismatch while skipping data descriptor")

          if ( $oldCrc32 != $self->{'crc32'}

            || $oldUncompressedSize != $self->{'uncompressedSize'});

        $self->{'crc32'} = 0 

            if $self->compressionMethod() == COMPRESSION_STORED ; 

    }

    return AZ_OK;

}

# Read from a local file header into myself. Returns AZ_OK if successful.

# Assumes that fh is positioned after signature.

# Note that crc32, compressedSize, and uncompressedSize will be 0 if

# GPBF_HAS_DATA_DESCRIPTOR_MASK is set in the bitFlag.

sub _readLocalFileHeader {

    my $self = shift;

    my $header;

    my $bytesRead = $self->fh()->read($header, LOCAL_FILE_HEADER_LENGTH);

    if ($bytesRead != LOCAL_FILE_HEADER_LENGTH) {

        return _ioError("reading local file header");

    }

    my $fileNameLength;

    my $crc32;

    my $compressedSize;

    my $uncompressedSize;

    my $extraFieldLength;

    (

        $self->{'versionNeededToExtract'}, $self->{'bitFlag'},

        $self->{'compressionMethod'},      $self->{'lastModFileDateTime'},

        $crc32,                            $compressedSize,

        $uncompressedSize,                 $fileNameLength,

        $extraFieldLength

    ) = unpack(LOCAL_FILE_HEADER_FORMAT, $header);

    if ($fileNameLength) {

        my $fileName;

        $bytesRead = $self->fh()->read($fileName, $fileNameLength);

        if ($bytesRead != $fileNameLength) {

            return _ioError("reading local file name");

        }

        $self->fileName($fileName);

    }

    if ($extraFieldLength) {

        $bytesRead =

          $self->fh()->read($self->{'localExtraField'}, $extraFieldLength);

        if ($bytesRead != $extraFieldLength) {

            return _ioError("reading local extra field");

        }

    }

    $self->{'dataOffset'} = $self->fh()->tell();

    if ($self->hasDataDescriptor()) {

        # Read the crc32, compressedSize, and uncompressedSize from the

        # extended data descriptor.

        # Skip over the compressed file data (assumes that EOCD compressedSize

        # was correct)

        $self->fh()->seek($self->{'compressedSize'}, IO::Seekable::SEEK_CUR)

          or return _ioError("seeking to extended local header");

        my $status = $self->_readDataDescriptor();

        return $status unless $status == AZ_OK;

    } else {

        return _formatError(

            "CRC or size mismatch after reading data descriptor")

          if ( $self->{'crc32'} != $crc32

            || $self->{'uncompressedSize'} != $uncompressedSize);

    }

    return AZ_OK;

}

# This will read the data descriptor, which is after the end of compressed file

# data in members that have GPBF_HAS_DATA_DESCRIPTOR_MASK set in their bitFlag.

# The only reliable way to find these is to rely on the EOCD compressedSize.

# Assumes that file is positioned immediately after the compressed data.

# Returns status; sets crc32, compressedSize, and uncompressedSize.

sub _readDataDescriptor {

    my $self = shift;

    my $signatureData;

    my $header;

    my $crc32;

    my $compressedSize;

    my $uncompressedSize;

    my $bytesRead = $self->fh()->read($signatureData, SIGNATURE_LENGTH);

    return _ioError("reading header signature")

      if $bytesRead != SIGNATURE_LENGTH;

    my $signature = unpack(SIGNATURE_FORMAT, $signatureData);

    # unfortunately, the signature appears to be optional.

    if ($signature == DATA_DESCRIPTOR_SIGNATURE

        && ($signature != $self->{'crc32'})) {

        $bytesRead = $self->fh()->read($header, DATA_DESCRIPTOR_LENGTH);

        return _ioError("reading data descriptor")

          if $bytesRead != DATA_DESCRIPTOR_LENGTH;

        ($crc32, $compressedSize, $uncompressedSize) =

          unpack(DATA_DESCRIPTOR_FORMAT, $header);

    } else {

        $bytesRead = $self->fh()->read($header, DATA_DESCRIPTOR_LENGTH_NO_SIG);

        return _ioError("reading data descriptor")

          if $bytesRead != DATA_DESCRIPTOR_LENGTH_NO_SIG;

        $crc32 = $signature;

        ($compressedSize, $uncompressedSize) =

          unpack(DATA_DESCRIPTOR_FORMAT_NO_SIG, $header);

    }

    $self->{'eocdCrc32'} = $self->{'crc32'}

      unless defined($self->{'eocdCrc32'});

    $self->{'crc32'}            = $crc32;

    $self->{'compressedSize'}   = $compressedSize;

    $self->{'uncompressedSize'} = $uncompressedSize;

    return AZ_OK;

}

# Read a Central Directory header. Return AZ_OK on success.

# Assumes that fh is positioned right after the signature.

sub _readCentralDirectoryFileHeader {

    my $self      = shift;

    my $fh        = $self->fh();

    my $header    = '';

    my $bytesRead = $fh->read($header, CENTRAL_DIRECTORY_FILE_HEADER_LENGTH);

    if ($bytesRead != CENTRAL_DIRECTORY_FILE_HEADER_LENGTH) {

        return _ioError("reading central dir header");

    }

    my ($fileNameLength, $extraFieldLength, $fileCommentLength);

    (

        $self->{'versionMadeBy'},

        $self->{'fileAttributeFormat'},

        $self->{'versionNeededToExtract'},

        $self->{'bitFlag'},

        $self->{'compressionMethod'},

        $self->{'lastModFileDateTime'},

        $self->{'crc32'},

        $self->{'compressedSize'},

        $self->{'uncompressedSize'},

        $fileNameLength,

        $extraFieldLength,

        $fileCommentLength,

        $self->{'diskNumberStart'},

        $self->{'internalFileAttributes'},

        $self->{'externalFileAttributes'},

        $self->{'localHeaderRelativeOffset'}

    ) = unpack(CENTRAL_DIRECTORY_FILE_HEADER_FORMAT, $header);

    $self->{'eocdCrc32'} = $self->{'crc32'};

    if ($fileNameLength) {

        $bytesRead = $fh->read($self->{'fileName'}, $fileNameLength);

        if ($bytesRead != $fileNameLength) {

            _ioError("reading central dir filename");

        }

    }

    if ($extraFieldLength) {

        $bytesRead = $fh->read($self->{'cdExtraField'}, $extraFieldLength);

        if ($bytesRead != $extraFieldLength) {

            return _ioError("reading central dir extra field");

        }

    }

    if ($fileCommentLength) {

        $bytesRead = $fh->read($self->{'fileComment'}, $fileCommentLength);

        if ($bytesRead != $fileCommentLength) {

            return _ioError("reading central dir file comment");

        }

    }

    # NK 10/21/04: added to avoid problems with manipulated headers

    if (    $self->{'uncompressedSize'} != $self->{'compressedSize'}

        and $self->{'compressionMethod'} == COMPRESSION_STORED) {

        $self->{'uncompressedSize'} = $self->{'compressedSize'};

    }

    $self->desiredCompressionMethod($self->compressionMethod());

    return AZ_OK;

}

sub rewindData {

    my $self = shift;

    my $status = $self->SUPER::rewindData(@_);

    return $status unless $status == AZ_OK;

    return AZ_IO_ERROR unless $self->fh();

    $self->fh()->clearerr();

    # Seek to local file header.

    # The only reason that I'm doing this this way is that the extraField

    # length seems to be different between the CD header and the LF header.

    $status = $self->_seekToLocalHeader();

    return $status unless $status == AZ_OK;

    # skip local file header

    $status = $self->_skipLocalFileHeader();

    return $status unless $status == AZ_OK;

    # Seek to beginning of file data

    $self->fh()->seek($self->dataOffset(), IO::Seekable::SEEK_SET)

      or return _ioError("seeking to beginning of file data");

    return AZ_OK;

}

# Return bytes read. Note that first parameter is a ref to a buffer.

# my $data;

# my ( $bytesRead, $status) = $self->readRawChunk( \$data, $chunkSize );

sub _readRawChunk {

    my ($self, $dataRef, $chunkSize) = @_;

    return (0, AZ_OK) unless $chunkSize;

    my $bytesRead = $self->fh()->read($$dataRef, $chunkSize)

      or return (0, _ioError("reading data"));

    return ($bytesRead, AZ_OK);

}

1;